With the development of radio communications technologies, radio access network architectures become diversified. At present, two existing radio access network architectures are provided:
1. Conventional radio access network architecture: In this architecture, a baseband is deployed in a site. Using long term evolution (Long Term Evolution, LTE) as an example, an access network uses an evolved universal terrestrial radio access network (Evolved Universal Terrestrial RAN, E-UTRAN) structure, where primarily a base station is connected to an access gateway by using an S1 interface, and base stations are connected to each other by using an X2 interface. This architecture has certain advantages in site deployment and is highly reliable; however, mutual transmission and processing of collaborative data between sites cannot be performed, and baseband consumption is high.
2. Centralized processing radio access network (Centralized Processing, Collaborative Radio, Real-Time Cloud Computing-Radio Access Network, C-RAN) architecture: This architecture puts a plurality of digital processing units (Cloud digital process units, Cloud DUs) together to implement centralized use of baseband processing resources. However, evolution from the conventional radio access network architecture to this structure causes a problem of a high deployment cost; moreover, because DUs are deployed in a centralized manner, disaster recovery cannot be implemented, resulting in poor availability of a site. In addition, after a DU is removed from a cabinet, it is possible that some devices that are originally controlled by the DU cannot work.